Field of the Invention
This invention relates to a device for attenuating noise generated by a pressurized fluid when released to the atmosphere, especially steam, for example from a geothermal power plant.
Electric power generation using steam from geothermal wells is of increasing importance, especially in view of escalating costs for petroleum-derived fuels. Serious difficulties, however, are experienced in using geothermal steam. Because of low quality of this steam (dirty steam), including its content of water, corrosive materials, such as hydrogen sulfide and the like, and of entrained solids, it is often necessary to discontinue flow the steam to the generator for purposes of upkeep and maintenance. It is usually impractical to suddenly interrupt flow from a geothermal well, for example by closing a valve. Unless continued flow is maintained, the well tends to deteriorate. Practice has been to by-pass the generator and vent the steam to the atmosphere, but this results in high noise levels. Unplanned steam releases are relatively frequent, large and lengthy at a geothermal power plant. Accordingly, some means for reducing noise is required.
Mufflers of the rock-filled type are known and used for attenuating noise generated by a pressurized fluid upon release to the atmosphere. These generally consist of a container filled with rock aggregate, typically of 1 to 6 inch screening. Steam is introduced at or near the bottom, passes through the body of the aggregate and exits from the surface. In order to prevent ejection of the fill, conventional rock filled mufflers are very large and hence costly and difficult to site. In general, the fill is not held in place by a screen or grill because a failure could cause a sudden dangerous ejection of hot rock.
Blow-off silencers fabricated of steel, steel and fiber glass combinations, and the like, see only limited use in geothermal service because of fatigue and corrosion problems and the resulting concerns regarding safety and reliability.
An object herein is to provide an improved blow-off muffler of reduced size, improved resistance to corrosion and reduced cost.
Other objects will be clear from the description to follow.